The Belle II experiment at the SuperKEKB electron-positron collider began physics datataking in 2019 with full detectors. The main goal of the Belle II is to search for new physics beyond the Standard Model in heavy flavor decays and Dark sector. In order to select events of interest efficiently under severe beam background environment from higher instantaneous luminosity run than the KEKB collider, we have upgraded a real-time hardware trigger system using the CsI(Tl) electromagnetic calorimeter. In this report, performance of the calorimeter trigger system under SuperKEKB Phase 3 operation is described. K: Trigger algorithms; Calorimeters; Trigger concepts and systems (hardware and software)1Corresponding author.